Health Impacts and Biomarkers of Prenatal Exposure to Methylmercury: Lessons from Minamata, Japan

The main chemical forms of mercury are elemental mercury, inorganic divalent mercury, and methylmercury, which are metabolized in different ways and have differing toxic effects in humans. Among the various chemical forms of mercury, methylmercury is known to be particularly neurotoxic, and was identified as the cause of Minamata disease. It bioaccumulates in fish and shellfish via aquatic food webs, and fish and sea mammals at high trophic levels exhibit high mercury concentrations. Most human methylmercury exposure occurs through seafood consumption. Methylmercury easily penetrates the blood-brain barrier and so can affect the nervous system. Fetuses are known to be at particularly high risk of methylmercury exposure. In this review, we summarize the health effects and exposure assessment of methylmercury as follows: (1) methylmercury toxicity, (2) history and background of Minamata disease, (3) methylmercury pollution in the Minamata area according to analyses of preserved umbilical cords, (4) changes in the sex ratio in Minamata area, (5) neuropathology in fetuses, (6) kinetics of methylmercury in fetuses, (7) exposure assessment in fetuses.

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Risk and Regulation: Methylmercury Exposure and Fish Consumption

Vanderbilt Undergraduate Research Journal ◽

10.15695/vurj.v6i0.2880 ◽

2010 ◽

Vol 6 ◽

Author(s):

Jonathan M Gendzier

Keyword(s):

Environmental Protection Agency ◽

Fish Consumption ◽

Government Regulation ◽

Mercury Emissions ◽

Methylmercury Exposure ◽

Exposure Levels ◽

Aquatic Food ◽

Reference Doses ◽

Fish And Shellfish ◽

Global Cycle

Exposure to organic mercury (methylmercury) occurs almost universally due to ingestion via contaminated fish and shellfish tissue. Ultimate sources of mercury consist of air release by domestic industrial combustion, mining, and international mercury emissions transported via a global cycle. Deposition of mercury from air to surface waters results in methylation to organic methylmercury and bioaccumulation in the aquatic food web. Health effects from methylmercury exposure consist mainly of neurological and neurodevelopmental effects, with fetuses particularly sensitive. Thus regulation of methylmercury exposure has concentrated on acceptable exposure levels and reference doses aimed toward protecting developing fetuses. The risk of methylmercury exposure in humans is regulated largely by the federal government, especially by the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA). The EPA imposes limits on mercury emissions and seeks to research methylmercury levels in fish and humans. The EPA sets a reference dose for methylmercury exposure. The FDA conducts uses date on methylmercury levels in fish to advise consumers on how to make informed decisions regarding fish consumption. There are numerous shortcoming to government regulation of this issue. Further scientific research, improved implementation of available data and scientific conclusions, and improved public communication of risk would all lead to more effective treatment of the risk of methylmercury exposure via ingestion of fish and shellfish. This could include more effective monitoring systems of human and fish methylmercury levels, research into the process of bioaccumulation, and implementation of stricter fish labeling standards, as well as research into higher-risk subpopulations allowing for targeted standards and recommendations.

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Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

Scientific Reports ◽

10.1038/s41598-021-95742-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Pianpian Wu ◽

Martin J. Kainz ◽

Fernando Valdés ◽

Siwen Zheng ◽

Katharina Winter ◽

...

Keyword(s):

Climate Change ◽

Fatty Acids ◽

Organic Matter ◽

Food Webs ◽

Essential Fatty Acids ◽

Trophic Levels ◽

Climate Change Scenarios ◽

Essential Nutrients ◽

Aquatic Food Webs ◽

Aquatic Food

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.

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Methylmercury exposure assessment using dietary and biomarker data among frequent seafood consumers in France

Environmental Research ◽

10.1016/j.envres.2007.12.005 ◽

2008 ◽

Vol 107 (1) ◽

pp. 30-38 ◽

Cited By ~ 42

Author(s):

Véronique Sirot ◽

Thierry Guérin ◽

Yves Mauras ◽

Hervé Garraud ◽

Jean-Luc Volatier ◽

...

Keyword(s):

Exposure Assessment ◽

Methylmercury Exposure ◽

Biomarker Data

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Gaseous mercury in coastal urban areas

Environmental Chemistry ◽

10.1071/en10088 ◽

2010 ◽

Vol 7 (6) ◽

pp. 537 ◽

Cited By ~ 3

Author(s):

Anne L. Soerensen ◽

Henrik Skov ◽

Matthew S. Johnson ◽

Marianne Glasius

Keyword(s):

Urban Areas ◽

Marine Boundary Layer ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Mercury Deposition ◽

Mercury Emissions ◽

Gaseous Elemental Mercury ◽

Gaseous Mercury ◽

Range Transport ◽

Aquatic Food

Environmental context Mercury is a neurotoxin that bioaccumulates in the aquatic food web. Atmospheric emissions from urban areas close to the coast could cause increased local mercury deposition to the ocean. Our study adds important new data to the current limited knowledge on atmospheric mercury emissions and dynamics in coastal urban areas. Abstract Approximately 50% of primary atmospheric mercury emissions are anthropogenic, resulting from e.g. emission hotspots in urban areas. Emissions from urban areas close to the coast are of interest because they could increase deposition loads to nearby coastal waters as well as contribute to long range transport of mercury. We present results from measurements of gaseous elemental mercury (GEM) and reactive gaseous mercury (RGM) in 15 coastal cities and their surrounding marine boundary layer (MBL). An increase of 15–90% in GEM concentration in coastal urban areas was observed compared with the remote MBL. Strong RGM enhancements were only found in two cities. In urban areas with statistically significant GEM/CO enhancement ratios, slopes between 0.0020 and 0.0087 ng m–3 ppb–1 were observed, which is consistent with other observations of anthropogenic enhancement. The emission ratios were used to estimate GEM emissions from the areas. A closer examination of data from Sydney (Australia), the coast of Chile, and Valparaiso region (Chile) in the southern hemisphere, is presented.

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Aquatic food web research in mesocosms: a literature survey

Journal of Limnology ◽

10.4081/jlimnol.2020.1949 ◽

2020 ◽

Author(s):

Csenge Póda ◽

Ferenc Jordán

Keyword(s):

Food Web ◽

Multiple Stressors ◽

Experimental Testing ◽

Literature Survey ◽

Trophic Levels ◽

Combined Effects ◽

Theoretical Concepts ◽

Aquatic Food ◽

Emerging Topics ◽

Web Research

Food web research feeds ecology with elementary theoretical concepts that need controlled experimental testing. Mesocosm facilities offer multiple ways to execute experimental food web research in a rigorous way. We performed a literature survey to overview food web research implementing the mesocosm approach. Our goal was to summarise quantitatively how the mesocosm approach has formerly been used and question how to best utilise mesocosms for the emerging topics in food web research in the future. We suggest increasing the number of replicates, extending the duration of the experiments, involving higher trophic levels and addressing the combined effects of multiple stressors.

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Patterns, dynamics and consequences of microplastic ingestion by the temperate coral, Astrangia poculata

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.0726 ◽

2019 ◽

Vol 286 (1905) ◽

pp. 20190726 ◽

Cited By ~ 19

Author(s):

Randi D. Rotjan ◽

Koty H. Sharp ◽

Anna E. Gauthier ◽

Rowan Yelton ◽

Eliya M. Baron Lopez ◽

...

Keyword(s):

Rhode Island ◽

Marine Invertebrates ◽

Trophic Levels ◽

Coastal Environments ◽

Monitoring Tool ◽

Astrangia Poculata ◽

Temperate Coral ◽

Inhibit Food Intake ◽

Aquatic Food ◽

Behavioural Dynamics

Microplastics (less than 5 mm) are a recognized threat to aquatic food webs because they are ingested at multiple trophic levels and may bioaccumulate. In urban coastal environments, high densities of microplastics may disrupt nutritional intake. However, behavioural dynamics and consequences of microparticle ingestion are still poorly understood. As filter or suspension feeders, benthic marine invertebrates are vulnerable to microplastic ingestion. We explored microplastic ingestion by the temperate coral Astrangia poculata . We detected an average of over 100 microplastic particles per polyp in wild-captured colonies from Rhode Island. In the laboratory, corals were fed microbeads to characterize ingestion preference and retention of microplastics and consequences on feeding behaviour. Corals were fed biofilmed microplastics to test whether plastics serve as vectors for microbes. Ingested microplastics were apparent within the mesenterial tissues of the gastrovascular cavity. Corals preferred microplastic beads and declined subsequent offerings of brine shrimp eggs of the same diameter, suggesting that microplastic ingestion can inhibit food intake. The corals co-ingested Escherichia coli cells with microbeads. These findings detail specific mechanisms by which microplastics threaten corals, but also hint that the coral A. poculata , which has a large coastal range, may serve as a useful bioindicator and monitoring tool for microplastic pollution.

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Selenium Interactions with Algae: Chemical Processes at Biological Uptake Sites, Bioaccumulation, and Intracellular Metabolism

Plants ◽

10.3390/plants9040528 ◽

2020 ◽

Vol 9 (4) ◽

pp. 528 ◽

Cited By ~ 2

Author(s):

Dominic E. Ponton ◽

Stephanie D. Graves ◽

Claude Fortin ◽

David Janz ◽

Marc Amyot ◽

...

Keyword(s):

Food Webs ◽

Mechanistic Model ◽

Trophic Levels ◽

Primary Producers ◽

Organic Selenium ◽

Selenium Uptake ◽

Aquatic Food Webs ◽

Uptake Sites ◽

Aquatic Food ◽

Lentic Systems

Selenium (Se) uptake by primary producers is the most variable and important step in determining Se concentrations at higher trophic levels in aquatic food webs. We gathered data available about the Se bioaccumulation at the base of aquatic food webs and analyzed its relationship with Se concentrations in water. This important dataset was separated into lotic and lentic systems to provide a reliable model to estimate Se in primary producers from aqueous exposure. We observed that lentic systems had higher organic selenium and selenite concentrations than in lotic systems and selenate concentrations were higher in lotic environments. Selenium uptake by algae is mostly driven by Se concentrations, speciation and competition with other anions, and is as well influenced by pH. Based on Se species uptake by algae in the laboratory, we proposed an accurate mechanistic model of competition between sulfate and inorganic Se species at algal uptake sites. Intracellular Se transformations and incorporation into selenoproteins as well as the mechanisms through which Se can induce toxicity in algae has also been reviewed. We provided a new tool for risk assessment strategies to better predict accumulation in primary consumers and consequently to higher trophic levels, and we identified some research needs that could fill knowledge gaps.

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The Lake Ontario Life Support System

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f87-274 ◽

1987 ◽

Vol 44 (12) ◽

pp. 2230-2240 ◽

Cited By ~ 28

Author(s):

D. R. S. Lean ◽

H-J. Fricker ◽

M. N. Charlton ◽

R. L. Cuhel ◽

F. R. Pick

Keyword(s):

Primary Productivity ◽

Life Support ◽

Lake Ontario ◽

Trophic Levels ◽

Phosphorus Concentration ◽

Nutrient Regeneration ◽

Particulate Carbon ◽

Calcium Carbonate Precipitation ◽

Mixing Processes ◽

Aquatic Food

Primary productivity provides most of the energy to support aquatic food chains. The rate is not only influenced by available solar radiation but also by temperature, availability of phosphorus, and the influence of physical mixing processes. The special features of Lake Ontario such as changes in phosphorus concentration, calcium carbonate precipitation, and silica deficiency on primary productivity, concentration of particulate carbon, and chlorophyll are discussed. Our lack of understanding of food chain and nutrient regeneration processes is illustrated through our failure to balance carbon production with losses through zooplankton grazing and sedimentation. It was demonstrated, however, that bacteria are not responsible for nutrient regeneration through "mineralization" but nutrients are effectively recycled in the water column at the second and third trophic levels.

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Species-specific content of thiamin (vitamin B1) in phytoplankton and the transfer to copepods

Journal of Plankton Research ◽

10.1093/plankt/fbaa015 ◽

2020 ◽

Vol 42 (3) ◽

pp. 274-285

Author(s):

Emil Fridolfsson ◽

Elin Lindehoff ◽

Catherine Legrand ◽

Samuel Hylander

Keyword(s):

Vitamin B1 ◽

Prey Type ◽

Water Soluble ◽

Trophic Levels ◽

Specific Content ◽

Feeding Experiments ◽

Per Se ◽

Aquatic Food ◽

Species Specific ◽

Important Building Block

Abstract Thiamin (vitamin B1) is primarily produced by bacteria and phytoplankton in aquatic food webs and transferred by ingestion to higher trophic levels. However, much remains unknown regarding production, content and transfer of this water-soluble, essential micronutrient. Hence, the thiamin content of six phytoplankton species from different taxa was investigated, along with the effect of thiamin amendment on thiamin content. Furthermore, thiamin transfer to copepods was estimated in feeding experiments. Prey type, not phytoplankton thiamin content per se, was the most important factor for the transfer of thiamin, as it was lowest from filamentous Cyanophyceae and highest from more easily ingested prey like Dunaliella tertiolecta and Rhodomonas salina. Cyanophyceae had the highest thiamin content of the investigated species, eightfold higher than the lowest. Phytoplankton varied in thiamin content related to the supply of thiamin, where thiamin addition enabled higher thiamin content in some species, while copepod thiamin content was less variable. In all, thiamin transfer is not only dependent on the prey thiamin content, but also the edibility and/or digestibility is of importance. Thiamin is essential for all organisms, and this study constitutes an important building block to understanding the dynamics and transfer of thiamin in the aquatic food web.

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